Type slug impact control in high speed chain printers



April 1968 c. J. ANTONUCCI 3,

TYPE SLUG IMPACT CONTROL IN HIGH SPEED CHAIN PRINTERS Filed Jan. 25,1967 2 Sheets-Sheet 1 A ril 23, 1968 c. J. ANTONUCCI 3,379,125

TYPE SLUG IMPACT CONTROL IN HIGH SPEED CHAIN PRINTERS Filed Jan. 25,1967 2 Sheets-Sheet. 2

United States Patent 3,379,125 TYPE SLUG IMPACT CONTROL IN HIGH SPEEDCHAIN PRINTERS Carmine J. Antonucci, Commack, N.Y., assignor to PotterInstrument Company, Inc., Plainview, N.Y., a corporation of New YorkFiled Jan. 25, 1967, Ser. No. 611,651 6 Claims. (Cl. 101--93) ABSTRACTOF THE DISCLOSURE The specification and drawings show a chain printer inwhich the type slugs are driven by free-flight hammers against a paperweb. The penetration of the slugs is controlled by a surface that runsparallel to the print line.

In this impact printer, printing slugs mounted on an endless belt areguided as they move along the print line. F-ree flight print hammersdrive the slugs against a printing surface and the guide serves to limitthe travel of a struck slug.

This invention, generally, relates to high speed impact printers and,more particularly, an improved chain printer.

For a long time, efforts have been made in an industry wide struggle toimprove the reliability of high speed printers, to make them moreeconomical to manufacture and easier to service.

A most troublesome aspect in a high speed chain printer is limiting orcontrolling the flight of a hammer after a firing pulse has been appliedto its operating coil.

It is a principal object of the present invention to provide a new andimproved high speed chain printer.

It is another object of the invention to provide a hammer stop structurethat effectively and economically controls the flight of the printinghammers.

A further object of the invention is the provision of a new high speedchain printer which permits substantial savings in space to be realized.

Briefly, a high speed printer in accordance with which the principles ofthe present invention are particularly applicable has the usualplurality of printing hammers with heads aligned along a printing line,along with a plurality of printing type each having a predeterminedindicia adjacent one end for impact printing. A suitable flexible meansmoves the plurality of printing type along the printing line.

A stop bar or rail structure in accordance with the invention has alength along the printing line at least as long as the plurality ofprinting hammers and has a stopping surface to stop the printing type ina predetermined position after having been struck by a printing hammer,which may be a so-called free flight printing hammer. Means are providedto maintain the printing type, not being struck along the printing line,in a predetermined nonprinting position.

The invention further resides in certain novel features of parts andfurther objects and advantages thereof will become apparent to thoseskilled in the art to which it pertains from the following descriptionof the presently preferred embodiment described with respect toaccompanying drawings in which similar reference characters representcorresponding parts in the several views, and in which:

FIGURE 1 is a view in perspective of component parts of a high speedprinter as they relate to the structure of the invention;

FIGURE 1a is a fragmentary view of the print chain of FIGURE 1;

FIGURE 2 is a view in perspective similar to FIGURE Patented Apr. 23,1968 1 showing one means for biasing the type slugs away from the paperto be printed upon;

FIGURE 3 is a view in perspective similar to FIGURE 2 showing a printersimilar to that shown in FIGURE 2 but modified by the omission of alower pivot for the type slugs;

FIGURE 4 is a detail, fragmentary view of a type slug and upperpositioning bar.

Referring now to FIGURE 1 of the drawings, the numeral 10 identifies aplurality of printing hammers of the impact type, and while theparticular hammers shown have heads 11 in alignment along a printingline 12, it will be understood that any suitable structural arrangementfor the hammers 10 will be satisfactory.

Since printing hammers of various configurations and their relatedmechanical and electrical operating (or energizing) equipment are wellknown in the art, an elaborate and further detailed description herewould seem to 'be inappropriate.

While any suitable flexible carrier may be used to move a plurality ofprinting type 13 along the printing line 12, the present descriptionrefers to the kind shown, described and claimed in co-pending patentapplication Ser. No. 509,501, filed Nov. 14, 1965, entitled High SpeedPrinter and assigned to the assignee as the present invention.Therefore, the flexible carrier will be referred to hereinafter as abelt 14.

Each one of the printing type 13 has an upper slot 1 5 and a lower slot16 on one side of a body 17 to receive the respective upper and loweredges of the belt 14. For a belt 14 constructed in the form of a timingbelt as in the aforementioned application, the slots 15 and 16 may havetheir inner surfaces contoured to fit the teeth on the belt, so thatthey are supported firmly in place. Alternatively, the slugs may belocated between the teeth 14', as shown in the drawings particularlyFIGURE 1a. A spring 18 may be positioned against the belt .14 with itsends in the slots to hold the printing type in position.

A preselected indicia 19 adjacent one end of each printing type israised in relief of suitable form for impact printing when an anvilsurface 20 behind the indicia 19 is struck by a hammer head 11. Aprinting media 21, such as paper, is movable, usually in step fashion,by any of the well known paper feed mechanisms, and an inking media 22of ribbon, preferably, approaches the printing media 21 at the printingline 12 from a diflerent angle to reduce the chance of smearing. Aplaten 23 is positioned to support the printing media 21 along theprinting line 12 .where impact by the hammers occurs.

During the interval that the printing type 13 are moved along theprinting line 12, they are guided within slots 24 and 25 formed in apivot bar 26 and a stop bar 27, respectively. At least a part 28 of thelower end of each printing type is formed to fit the slot 24 withsuflicient closeness so that the type are constrained for guidingpurposes, yet with sufiicient looseness to permit each type to bepivoted slightly about the edge 29 when the anvil surface 20 is struckby a hammer head 11.

At least a part 3% of the upper end of each printing type is formed tofit the slot 25 with a looseness that is predetermined to give aclearance 31 which matches closely the desired distance of hammer travelduring impact. As a practical matter, the dimensions of the slot 25 aswell as the opposite surfaces of the part 30 may be machined with a highdegree of accuracy, thus providing the desired clearance 31.

Moreover, with the plurality of type 13 moving past the reverse side ofthe media 2!1 from the side normally viewed (along arrow 32), a slightamount of sliding of the type on the media can be tolerated. The mediais advanced rapidly enough to avoid wear of the media. A

small degree of wear of the type indicia would occur. However, suchindicia do not wear excessively, and when they do become worn to thepoint that legibility is impaired, they are replaceable readily, eitherindividually or all of the printing type at the same time.

With the construction in accordance with the present invention, periodicmaintenance is reduced to a minimum, and the time involved is reducedalso. It should be noted that replacing any one of the printing type notonly replaces a worn indicia 19 but, also, replaces the guide surfaceson the lower part 28 and the upper part 30.

Another reason or explanation that has been advanced for the parts 28and 30 and for the surfaces of the slots 24 and 25 not wearing to anysignificant extent is that the rapidly moving printing type sweepmolecules of air into the slots, and this provides just enough of alubricant action.

While it is expected that the usual tension in the printing media 21,together with the angle of partial wrap around arcuate surfaces 33 and34 on the bars 26 and 27 would provide sufiicient tautness in the media21 for printing purposes, suitable pressure pads 35 and 36 areillustrated as another satisfactory means of accomplishing this result.Of course, bars may be used instead of individual, edge mounted pads ifdesired, and the inking media 22 in that case would wrap around suchbars also but would still be directed away from the printing media 21 ata dilferent angle to avoid smear and, also, to move away from the lineof vision 42.

It has been mentioned before that the clearance 31 is significant inthat it represents a distance of travel for each indicia 19 forimpacting against the media 21 and, therefore, is a significant factorin predetermining the hammer firing time. Such firing time is initiatedin advance of the type arriving at the desired position in order toallow for all of the delays usually involved, such as inherent delayswithin the magnet energizing circuit to actuate the mechanical hammerand, also, for the interval of time required for the printing type tomove the distance that is represented by the clearance 31.

While the structure shown in FIGURE 1 contemplates any suitablearrangement for maintaining the part 30 normally along the oppositesurface of the slot 25 (because this view shows the type 13 in theprinting or impact position), the arrangement shown in FIGURE 2illustrates a convenient structure for obtaining this result. This viewshows the clearance 31 on the opposite side of the part 30 from thatshown in FIGURE 1 and illustrates the position usually occupied by theprinting type 13 as they traverse the slots 24 and 25.

To maintain the printing type 13 so that the part 30 forms the clearance31 as shown in FIGURE 2, the belt 114 is supported so that it passesalong the printing line 12 at a preselected angle of the variousarrangements that are available for obtaining the belt in this position,the structure of FIGURE 2 contemplates the axis 37 of rotation for thebelt support cylinder 38 being offset by an angle indicated by thenumeral 39 from a line 40 which is parallel with a line drawn throughthe surface of the slot 25 adjacent the clearance 3 (FIGURE 2) andthrough the edge 29.

It should be noted that the print hammers 11 and type slugs 13' lie onthe same side of the web 22. This permits the hammers to be positionedwithin the loop formed by the print chain, resulting in the substantialsavings in space.

In some situations, particularly where the width of the printing line isrelatively small, the arrangement shown in FIGURE 3 is quite useful.This structure is characterized by a smaller body 41 of printing type 42which is permitted largely because of the type having only a stop bar 27common to all the type. Since the printing line is short, the smallstiffness inherent in the flexible belt 14 is suflicient to maintain theclearance 31 normally as shown in FIGURE 3. In other words, a lowerpivot bar is not necessary in this arrangement.

The usual tautness of the printing media 21 may, in the structureillustrated, be relied upon to maintain the media under control over theprinting line. To assist in this, guide blocks 43 and 44 are positionedalong the edge opposite from that under the guiding control of the stopbar 27.

As described in connection with the structure shown in FIGURE 2, theaxis of rotation 37a in FIGURE 3 is offset, as already described, sothat the clearance 31 is as illustrated without the necessity of furtherstructure. The angle 39a of such olfset is at least, and preferablyslightly greater than, the angle measured from a line 40a. which isparallel to a line through the surface of the slot 25 adjacent theclearance 31, FIGURE 3.

Referring now to FIGURE 4, the anvil 20 of each type bar 13 may beformed with a magnetic region 64 which cooperates with a magnetic region67 of opposite polarity on the stop bar 27 in order to return the bar 13to a retracted position after printing.

While there has been shown and described and pointed out the fundamentalnovel features of the invention as applied to a preferred embodiment, itwill be understood that various omissions and substitutions and changesin the form and details of the device illustrated and in its operationmay be made by those skilled in the art without departing from thespirit of the invention. It is the intention, therefore, to be limitedonly as indicated by the scope of the following claims.

What is claimed is:

1. In a high speed printer of the chain type having:

a plurality of printing hammers with heads aligned along a printingline,

39 a plurality of elongated printing type slugs each having apredetermined indicia formed on one side of said slug adjacent one endfor impact printing,

said hammers disposed to strike said slugs on the side opposite said oneside,

flexible means for moving said plurality of printing type slugs alongthe printing line, and

guide means for guiding said plurality of printing type slugs along theprinting line,

said guide means comprising:

stop bar means having a length along the printing line at least as longas the plurality of hammers and having a stopping surface to contactsaid slugs at said one end to stop the printing type slugs when struckby a printing hammer, and

pivot bar means having a length along the printing line at least as longas the plurality of hammers and having a surface disposed adjacent theother end of said slugs against which the printing type slugs pivot whenstruck by a printing hammer.

2. In a high speed printer as set forth in claim 1 wherein said stop barmeans has a slot extending throughout the length of said printing lineand a width equal to the distance of travel predetermined for saidprinting type and said stopping surface is one side of said slot.

3. In a high speed printer as set forth in claim 2 including means tobias the plurality of printing type along the printing line in adirection away from said stopping surface.

4. A high speed printer of the chain type comprising;

a plurality of printing hammers with heads aligned along a printingline,

a plurality of printing type slugs each having a predetermined indiciaon one side of said slugs for impact printing,

means for moving said plurality of printing type slugs along theprinting line,

said printing hammers disposed to strike said slugs on the side oppositesaid one side,

a stop bar means having a stopping surface disposed to limit themovement of a type When struck by a printing hammer, and

means to maintain said plurality of printing type slugs that moves alongsaid printing line normally in a retracted non-printing position.

5. A high speed printer of the chain type as set forth in claim 4wherein said stop bar is one side of a channel that extends along saidprint line and said slugs contact the other side of said channel in theretracted, non-printing position.

6. In a high speed printer as set forth in claim 3 further includingmeans to twist said flexible means so that said slugs ride against theother side of said slot.

References Cited UNITED STATES PATENTS WILLIAM B. PENN, PrimaryExaminer.

